package com.study02;

public class NoteBook {
    public void run(){
        System.out.println("开启电脑");
    }

    public void useUSB(USB usb, String power){
        if(usb != null && power == "有电"){
            usb.open();
            usb.close();
        }
    }

    public void shutDown(){
        System.out.println("关闭电脑");
    }
}
